Device for metal cutting

ABSTRACT

A device for the cutting metal-machining of one of several workpieces clamped on pallets (WP) and held ready in a device for holding several such pallets (WP) with a control device for timed sequence control, the conveyance of the preselected pallet (WP) bearing a workpiece from the preparation (18) to the machining position (BP), a tool spindle unit changing device for preparing a preselected tool spindle unit (10) in its operative position (AP), a tool changing unit (14, 31) to prepare and take the preselected drilling, milling or grinding tool (WZ) from a tool magazine (14) into the sleeve (13) of the tool spindle unit (10) and a device in the form of a pallet magazine (PM) to take at least two workpiece pallets (WP) which has at least one preparation position (18) arranged in the vertical plane and in which the clamping position (17) is horizontal, and a conveyor (ZU) for bringing at least one loaded pallet (WP) from the preparation (18) to the machining position (BP) of the workpiece carrier (WT) having a conveyor path (20) for the pallet (WP) which can be connected to the preparation position (18) on the one hand and the machining position (BP) of the workpiece carrier (WT) on the other hand and can pivot through 180°.

The invention refers to a device for metal cutting one of moreworkpieces mounted on workpiece pallets and readied for use in areceiving apparatus for several workpiece pallets for transport into themachining position.

Devices of this type were already proposed, which include a control unitfor clocked sequence control of several machine operations partially atthe same time or also partially in succession, by feeding a preselectedworkpiece pallet, which is loaded with a workpiece from a pickup site tothe machining position, and by inserting a preselected machining tool bymeans of a tool changing apparatus into the sleeve of the tool spindleunit.

Tool magazine and changing device ensure an automatic tool supply suitedto the respective machining task.

Thereby it is required to design the tool carrier of the working machineand its clamping plate for receiving the workpiece pallet accurate todimension.

Charging of the workpiece pallet with workplaces selected for machiningis executed at a pallet assembly site. There, the workpieces areadjusted accurate to dimension by a clamping fixture, to which theworkpiece pallet are mounted and then transported to the pickup site.

At the time of the workpiece change, the workpiece pallet is transportedby hand or by means of a loading unit, e.g. a grab or a hoist--whenheavy workpieces are concerned--into the machining position onto theworkpiece carrier of the working machine from which the previouslymachined workpiece is released and removed.

Further, feeding devices, which are movable along guide tracks, areknown for use with workpiece pallets. Moreover, it has already beenproposed to arrange several pickup sites for workpiece pallets, loadedwith workpieces, on a common assembly which may be rotatable in acarousel-like manner or may be similar to a conveyer path. At least oneof the existing loading sites of the assembly must be lockable in aposition in which the change of the workpiece pallet can be executed insuch a manner that the machined workpiece is removed from the assemblyand a still unfinished workpiece mounted onto the workpiece palletoccupies the freed loading site.

There is always the need with regard to such assemblies on workingmachines to execute the individual functions and changing operations asrapidly and simply as possible in order to keep the mechanical andcontrol parts to a minimum. Starting out from these realities, asignificant simplification is effected, in accordance with a teaching ofthe invention, when providing a receiving apparatus formed as palletmagazine for at least two workpiece pallets with at least one pickupsite in a vertical plane and with the charging and clamping site beingdesigned horizontally.

When the pickup site of the pallets for the workpieces being fed formachining is arranged according to the invention in a vertical plane,then the workpiece pallets can be transferred in this vertical planedirectly, i.e. without additional swinging or tilting motions into themachining position and secured to the workpiece carrier. This is inparticular advantageous when the workpiece is formed as ahorizontal-axial body of rotation and the tool carrier includes a pivotdrive; then, the body of rotation can then additionally be supported ina fixed stay and/or in a tailstock. Further, the design with ahorizontally aligned loading and clamping site is advantageous, inparticular as far as heavy workpieces are concerned which possibly isrequired to be fed by a conveyor. Thus, the clamping and adjusting bymeans of a readied apparatus upon the workpiece pallet can be executedin a simple manner without significant manual strain or manipulations.

Of great relevance appears the provision of the further embodimentaccording to the invention of a feeder for at least one loaded workpiecepallet from the pickup site to the machining position of the workpiececarrier, which feeder includes for the workpiece pallet a conveying pathconnectable to the pickup site, on the one hand, and to the machiningposition of the workpiece carrier, on the other hand. In accordance witha preferred embodiment, the feeder is formed as a linear, i.e.rectilinear conveying path, and swingably supported by 180°.

In accordance with further essential features of the invention, thepallet magazine, having at least two loading sites for workpiecepallets, is swingable about a horizontal axis and lockable in the numberof swing positions in correspondence to the number of loading sites, andfurther, it is in particular advantageous when the loading sites of thepallet magazine and/or the workpiece pallets and the feeder as well asthe workpiece carrier are provided with mounting elements by which theworkpiece pallets are adjustably secured onto the loading sites withregard to the feeder and the workpiece carrier. This ensures that theworkpiece pallets are securely connected in each position of movement ofthe pallet magazine and/or the feeder with their associated loading ortransport site.

Thereby, it is essential that the locking can be activated and releasedwithout any loss of time. This is made possible by providing the loadingsites with guide rails in correspondence to the standardized workpiecepallets and with clamping claws which are pressable by means of springpressure action against the pallet guides. The precise position of thepallets is ensured in a manner known per se through stops or throughcomplementary form fitting adjusting elements.

In order to further guarantee this assurance, provisions must be made toallow release of this clamping force only when the respective workpiecepallet is to be removed or replaced from its respective site. Thus, thedevice is designed in such a manner that the clamping of thestandardized workpiece pallets in the guide grooves of the loading sitesis releasable only in the swinging position of the feeder in which thepallet change is possible by means of a ram which is driven inopposition to the spring pressure by the feeder-pivot drive and lockedtherewith.

According to a further feature, it is furthermore advantageous toprovide the standardized workpiece pallets with recesses and theconveying path with engagement elements which engage the recesses forgrasping and further transport of the workpiece pallets which arereadied at the pickup site in the pallet magazine and in the machiningposition of the workpiece carrier. These standardized workpiece palletscorrespond essentially to DIN standards; they are, however, provided ontwo side edges with opposing lugs in which the recesses are formed forengagement of the engagement elements. The simplest embodiment includesthat in vertical position of the workpiece pallet, the lugs arranged onboth sides in horizontal direction are provided with vertical groovesfor engagement of engagement elements in form of engagement bolts.

An advantageous embodiment may include as an essential feature of theinvention to provide the conveying path of the feeder as chain conveyor,with the arrangement being made such that the driving strand of thechain conveyor is connected to the chain conveyor driving motor, with adrive shaft being arranged in the horizontal pivot axis of the feederand supporting a driving pinion which engages the conveyor chain.

In accordance with a variation of this embodiment, the conveying pathmay also be made of two parallel threaded spindles with threaded nutswhich include engagement elements engaging recesses of the workpiecepallets, whereby the threaded spindles are provided with right-handedthread and left-handed thread and/or driven in opposite direction.

In accordance with another preferred embodiment, the conveying path isformed by two racks moving in opposition to each other and includingengagement elements on both its extendible ends, with the engagementelements being formed on the side of the pickup site and the side of theworkpiece carrier for simultaneous bilateral engagement into therecesses of the workpiece pallets. This embodiment appears particularlysimple and operationally reliable.

In accordance with a further variation of the invention, it is alsopossible to form the engagement elements for bilateral and simultaneousengagement in the recesses of the workpiece pallets on the side of thepickup site side and on the side of the workpiece carrier side, or,furthermore, to provide the conveying path in form of two opposinglydriven, telescopic rods, with their bilateral extendible ends beingprovided with engagement elements for simultaneous, bilateral engagementin the recesses of the workpiece pallets at the side of the pickup siteand at the side of the workpiece carrier.

In the embodiment of the conveying path with threaded spindles, racks ortelescopic rods, the engagement elements may also be formed as steerableor disengageable, hook-like engagement catches, which engage the groovesor like recesses in the bilateral lugs of the workpiece pallet.

Within the scope of the invention is also the further design of thedevice in form of a highly automated manufacturing center throughcombination with an apparatus for changing the tools between the toolmagazine and the tool spindle or tool spindle unit situated in theworking position, as well as the tool spindle unit from its stand-byposition into the working position.

The first mentioned apparatus includes a power-actuatable tongs-typegrab that is shiftable and rotatable as well swingable and includes grabjaws which can open and close and can be aligned with the respectivetool removal axis and the spindle axis.

The tool spindle unit changing apparatus according to the invention isprovided with a vertical column console arranged on a common machinestand as well as with a tool spindle unit operatively connecteddetachably and exchangeable with the column console and a (first)movement path underneath the tool spindle unit which is operativelyconnected with the column console for directional displacement of thetool spindle unit detached from the column console from its workingposition into a stand-by position which is spaced from the columnconsole.

This solution includes a device part which combines the common toolstand unit with the device part for rapid automated changing of thetools and which adds a further dimension with regard to selection ofsequentially used tools. There is no need to select the tools on thebasis of available tool holder or spindle of the tool spindle but allneeded machining operations can be executed with different tools inrandom sequence in a same workpiece clamping fixtures regardless of thetool size and its taper or shank size.

The movement path may be designed as rail track, and the tool spindleunits may be provided with rollers for guidance thereon. Moreover, it ispossible to arrange special rolling containers which travel on the railtrack for receiving tool spindle units and for transporting, e.g.lifting, them into a stand-by position. Also, the movement path may bedesigned as suspension path by which the tool spindle units are loweredinto their stand-by position.

In accordance with a modification thereof, the movement path may beformed by a belt conveyor or plate conveyor on which the tool spindleunits are lowered and lifted therefrom in the area stand-by position orare moved to the side.

In accordance with a preferred embodiment, the movement path is arailroad-like rail track on which the tool spindle units easily travelvia sliding means or rollers, with the movement path including inaccordance with a further proposal an elevatable and lowerable sectionbeneath the working position of the tool spindle unit which is arrangedon the column console. This section is lifted below the tool spindleunit for receiving same so that the connection to the column console canbe separated and the tool spindle unit rests on the movement path or ona rolling container traveling thereon. In accordance with a variation ofthe invention, the column console or its adapter element for thedetachable connection with the tool spindle unit may be lowerable fromthe respective working position so that the tool spindle unit beingreplaced can be lowered onto the movement path and advanced from there.

Depending on the selected configuration of the movement path and itscharacteristics--as described above for example as conveyer or assuspension track--the movement path is sufficient for receiving andtransporting and feeding the tool spindle units being respectivelyreplaced because they can be transferred in a stand-by position by otheradditional lifting tools or transfer assemblies.

In accordance with a preferred embodiment, the arrangement is providedin such a manner that the (first) movement path has on its end a branchor a rotating disk which is connected to a further (second) movementpath designed as stand-by position for a plurality of tool spindle unitsor leading thereto, with a particularly advantageous arrangement beingcreated in such a manner that the first movement path is rectilinear,and the second movement path which is connected to the end thereof at aright angle at both sides is designed as stand-by position for aplurality of tool spindle units. In this manner, the tool spindle unitswith different tool receptacles or spindles and provided in stand-byposition become accessible at all times for differently sized tools;then, it is also possible to replace the tool spindles in case of needor to provide them with particular holding fixtures for special tools.

In accordance with further advantageous particulars of the deviceaccording to the invention, the tool spindle units are provided with asynchronous motor arranged directly on the spindle shaft and arespeed-controlled by a frequency converter. Moreover, an exchange of thetool spindle units is further especially simplified when, according to afurther feature, the adapter element of the column console and theattachment surface of the tool spindle units are provided withremote-controlled, pressure fluid operated fitting devices and armaturedevices and quick connections for the current transmissions.

In a machining center designed in accordance with the invention, thetool magazine, the tool changing unit and the changing device for thetool spindle units ensure an automatic, essentially freely shapeabletool supply in accordance with the respective machining tasks; thus, thebasis for high automation stages is established.

The following exemplified embodiment of the invention shows furtheradvantageous features and particulars which are described and explainedin more detail with reference to the illustration in the drawings, inwhich

FIG. 1 is a schematic overall top view of a highly automatedmanufacturing center, encompassing the concepts according to theinvention;

FIG. 1a is a schematic illustration of a tool changing device;

FIG. 1b is the illustration according to FIG. 1a in a modifiedconfiguration;

FIG. 1c illustrates a plan view of the column console of the device ofFIG. 1 in engagement with a tool spindle unit;

FIG. 1d is a side view thereof;

FIG. 2 is a schematic top view of the workpiece pallet changing unit;

FIG. 3 is an illustration according to FIG. 2 in viewing direction ontothe feeder pivot axis and the spindle axis of the tool spindle unit;

FIG. 4 is an illustration according to FIG. 3 in viewing direction ofthe horizontal axis of the pallet magazine;

FIG. 5 is a modified illustration according to FIG. 3;

FIG. 6 shows the feeder with chain conveyer;

FIG. 7 shows the feeder with a rack conveyer;

FIG. 8 shows a top view of the feeder with a rack conveyer;

FIG. 9 shows the feeder with a modified rack conveyer;

FIG. 10 is a top view of the feeder with a modified rack conveyer;

FIG. 11 shows the feeder with a threaded spindle conveyer;

FIG. 12 is a top view of the feeder according to FIG. 11;

FIG. 13 shows the feeder with a telescopic conveyer;

FIG. 14 is a top view of the feeder according to FIG. 13;

FIG. 15 shows the clamping unit for the workpiece pallets;

FIG. 16 is a partially sectional view of the clamping unit according toFIG. 13.

FIG. 1 shows a highly automated machining center created by the deviceaccording to the invention and united on a machine stand 1. Thismachining center includes a tool magazine console 2 with the toolmagazine 14 and a column guide 3 on which the column console 4 travels.Further provided is a tailstock guiding mechanism 5 for enabling atraveling of the tailstock 6. 7 designates an automatic pallet transfermechanism.

Provided on the column console 4 is a vertically movable adapter element45 with the attachment surface 46 for connection of the tools spindleunit 10.

FIG. 1 further shows how the tool spindle unit 11 provided in stand-byposition 16 of the tool spindle unit changing device slides on a guidingpath or movement path 44 extending in transverse direction R to thespindle axis Z and is transferable from a changing position 42 via abranch or rotating disk to a working position AP along a guiding path 43extending coaxially to the spindle axis Z. Traveling therealong is thetool spindle unit 10 or 11 until reaching the column console 4 forconnection to the attachment surface 46. This arrangement allows arandom exchange of the tool spindle units 10, 11.

The guiding path 43 is a railroad-like rail track on which the toolspindle units 10 easily travel via sliding means or rollers, andincludes a an elevatable and lowerable section 43a (FIGS. 1c, 1d)situated beneath the working position AP of the tool spindle unit 10 inengagement with the column console 4 via a dovetail joint 45a. Thissection 43a is lifted below the tool spindle unit 10 for receiving sameso that the connection to the column console 4 can be separated and thetool spindle unit 10 rests on the guiding path 43. In accordance with avariation of the invention, the column console 4 together with itsadapter element 45 may be lowerable relative to its base 4a running onthe column guide 3 for disengagement from the tool spindle unit 10 sothat the tool spindle unit being replaced can be lowered onto thesection 43a, as shown in FIG. 1c.

The tool spindle units 10, 11 are provided with a synchronous motorarranged directly on the spindle shaft and are speed-controlled by afrequency converter. The frequency generator for the synchronous motoris arranged in the area of the adapter element 45 of the column console4 for detachable connection with the tool spindle unit 10 situated inworking position AP in or on the column console 4. The adapter element45 of the column console 4 and the attachment surfaces 46 of the toolspindle units 10 are provided with remote-controlled pressure fluidoperated fitting and armature devices and rapid connections for thecurrent transmission.

The tools WZ are held in the tool changing unit 14 and inserted in thespindle 13 by a tongs-type grab ZG of the tool changing unit 31, secondto the console 4 by mounting 40.

FIGS, 1a,1b illustrate the tool change with the tool change unitaccording to the invention. The structure of the tool change unitincludes an arrangement of the tongs-type grab ZG which is pivotableabout a horizontal axis V on a console 40 which is rotatable by 90°about a vertical axis W by means of a power drive and is moved along aguiding path 41 in direction parallel to the tool spindle axis Z about astroke step H into its changing position for grasping the tool W. Onlyone stroke in direction of the spindle axis Z is necessary in order toremove the tool grasped by the tongs ZG from the spindle 13. Twosolutions are illustrated in FIGS. 1a and 1b. According to FIG. 1a, thecolumn console executes a return stroke H2 and a forward stroke H3 afterpivoting the tongs-type grab by 180° in order to insert the exchangedtool into the spindle 13.

The changing of a tool WZ with a same or differently sized shank ortaper is provided according to FIG. 1b in a manner that in the initialposition A of the double tongs-type grab ZG the first tongs Z1 graspsthe first tool WZ1 situated in the tool magazine 14 and that throughshifting about the stroke step H and turning of the console 40 by 90°about the vertical axis W the second tongs Z2 grasps a second tool WZ2situated in the spindle and pulled out from the spindle 13 by a secondstroke step H2. Thereafter, the first tool WZ1 is positioned before thespindle 13 through pivoting of the tongs-type grab ZG by 180° about thehorizontal axis V and inserted in the spindle 13 through executinga--third--reversing stroke step H3. Through turning back the console 40by 90° about the vertical axis W and shifting about the base stroke stepH, the tongs-type grab ZG travels into the initial position A in whichthe second tool WZ2 is placed into the tool magazine 14. As shown inFIG. 2, the feeder ZU can occupy a horizontal (illustrated in dashedline) and a vertical position by being swingable about the pivot axis 50which is arranged with the pivot drive in the frame 47. In thehorizontal position, the conveying path 20 which is not shown in detailis connected on both sides with the guide rails FL of the pallet guidesPF of the workpiece carrier WT and the pallet magazine PM, as is alsoshown in FIG. 3. FIG. 2 further illustrates the clamping position 17 forholding the work piece pallet WP in a horizontal position , and moreoverthe pickup position 18 in which the workpiece pallet WP standsvertically for transfer to the machining position and is held in thepallet guide PF which is in alignment with the conveying path 20 of thefeeder.

FIGS. 3 and 4 show further details of the cooperating components, thatis the pallet magazine pivotable about the horizontal axis X, and formedwith four loading sites 21 for receiving a workpiece pallet WP at theclamping position 17 and transporting the workpiece pallet WP to thepick-up position 18 for transfer to the machining position BP by thefeeder ZU 19 designates the tool carrier unit which is provided in theexemplified embodiment with a pivot drive 48 so that an axially centeredworkpiece can be machined in a machining position BP while beingrotated. The feeder ZU with the conveying path 20 is swingably supportedabout the pivot axis 50 on the frame 47.

FIG. 5 corresponds essentially to the embodiment according to FIG. 3,with the difference being that the feeder ZU has a longer and a shorterarm. This embodiment is suitable when the (in FIGS. 3, 4, and 5) notshown tailstock guiding mechanism 5 is situated too high to enable apassage of the feeder. In this case, the feeder ZU cannot travel a fullcircle of 360° or twice 180° so that the tool change requires twoseparate successive operations. At first, the workpiece pallet WP mustbe picked up from the tool carrier WT by the feeder ZU--as shown indashed line--and transported through swinging about 180°--see arrowdirection--to a free stand-by position 16 of the pallet magazine PM, andplaced thereon, Thereafter, the pallet magazine swings about 90° or 180°and a loaded workpiece pallet WP is moved to the stand-by position 16for removal by the conveyor 20 of the feeder ZU and transfer to theworkpiece carrier WT through swinging about 180°.

FIG. 6 illustrates a side of the feeder ZU with the chain conveyor 27 inwhich the conveyor chain 29 is guided via a driving pinion 30. Theconveyor chain 29 is equipped with an engagement element 26--formed aspin--which--as shown--engages the recess 33 on the lateral lug 49 of theworkpiece pallet WP for conveying the workpiece pallet WP into thedashed position.

FIGS. 7 and 8 show an embodiment of the feeder ZU with a rack conveyorhaving essentially the two racks 36 which are driven by a common or bytwo separate driving pinions 51. The rack strokes are defined in such amanner that the engagement elements 34 transport the workpiece pallet WPto the middle and then are disengaged or engaged in order to enable thesubsequent sequence stroke into the respectively other end position.

A modified rack design of the conveying path 20 of the feeder ZU isshown in FIGS. 9 and 10. There, each of the racks 36 is driven by twoseparate driving pinions 51 which are offset to the center for spacereasons. Thus, the racks 36 can be moved closer together. They are alsoprovided with the engagement elements 34 which engage in recesses 33 ofthe workpiece pallets WP.

FIGS. 11 and 12 show a conveyor design of the feeder ZU in form ofthreaded spindles 32 which are driven by a central gearing 52 andinclude at their ends engagements elements 34 by which they areinitially transported within the respective recesses 33 of the workpiecepallets to the center by one rack and then taken over by the other rackfor executing the remaining stroke.

Finally, FIGS. 13 and 14 show a schematic exemplified embodiment of adesign with telescopic rods 37. This embodiment has the advantage oflittle demand for space because the actual driving component is arrangedoutside of the device in form of a pressure fluid generator and pressurefluid control unit and requires only flexible tubes for connection tothe telescopic rods 37.

FIGS. 15 and 16 show an example as to how the clamping claws 23 arepressed under the action of the compression springs 22--here designed asdisk springs--onto the surfaces of the pallet guides PF. To release theclamping action, rams 25 are provided which are driven in a not shownmanner by means of lever action through the swinging motion of thefeeder ZU such that they permit in each changing position the release ofthe workpiece pallet to be changed.

We claim:
 1. Device for metal cutting of one of several workpieces (W)clamped on workpiece pallets (WP) and readied in a receiving unit forseveral workpiece pallets (WP) for transport into a machining position(BP), comprisinga. a control unit for clocked sequence control, b. apallet magazine (PM) containing at least two workpiece pallets (WP) andincludingat least two loading sites (21) for transporting a workpiecepallet (WP) from a clamping position in which the workpiece pallet is inhorizontal disposition to a pickup position (18) in which the workpiecepallet is in vertical disposition, wherein the pallet magazine (PM) isswingable about a horizontal axis (X) and securable in a number of swingpositions corresponding to a number of loading sites (21), c. a feeder(ZU) for transporting the workpiece pallet from the pickup position (18)to a machining position (BP) said feeder (ZU) being swingably supportedabout a horizontal axis (50) for movement by 180° and forminga conveyingpath (20) for the workpiece pallet (WP) between the pickup position andthe machining position (BP), d. a tool spindle unit changing device forpreparing a preselected tool spindle unit (10) in its working position(AP), said tool spindle unit changing device includingd1. a verticalcolumn console (4) arranged on a common column machine stand (1) and d2.a tool spindle unit (10) detachably and exchangeably connected to thecolumn console, wherein the tool spindle unit (10) is movable along aguiding path between a working position (AP) in which the tool spindleunit (10) is operatively connected with the column console (4) and astand-by position (16), as well as e. a tool changing unit (14, 31) forpreparing and feeding the preselected drilling, milling or grinding tool(WZ) from a tool magazine (14) into the sleeve (13) of said preselectedtool spindle unit (10).
 2. Device according to claim 1 wherein the toolspindle unit changing device has means for placement of a preselectedtool spindle unit (10) in its working position (AP), and includinga toolchanging unit (14, 31) for preparing and feeding the preselecteddrilling, milling or grinding tool (WZ) from a tool magazine (14) intothe sleeve (13) of said preselected tool spindle unit (10), wherein thetools (WZ) held in the tool magazine (14) in a horizontal axis areremovable by means by a double tongs-type grab (ZG) which is pivotableabout a horizontal axis (v) and arranged on a console (4) rotatableabout a vertical axis (w) by means of a power drive and is movable backand forth in direction parallel to the tool receiving axis and spindleaxis (Z) along a guiding path about at least one stroke step.
 3. Deviceaccording to the claim 1 wherein the loading sites (21) of the palletmagazine (PM) and the workpiece pallets (WP) and the feeder (ZU) as wellas the workpiece carrier (WT) are provided with mounting elements (39)by which the workpiece pallets (WP) are adjustably secured on theloading sites (21), the feeder (ZU) and the workpiece carrier (WT). 4.Device according to claim 3, wherein the loading sites (21) are providedwith guide rails (FL) in correspondence to the standardized workpiecepallets (WP) and with clamping claws which are pressable onto the palletguide (PF) by the action of a spring force (22).
 5. Device according toclaim 1 wherein in the initial position of the double tongs-type grab(ZG) a first tool (WZ) situated in the tool magazine (14) is grasped bythe first tongs (Z1) and through movement by a stroke step and turningof the console (40) by 90° about the vertical axis (w) a second tool(WZ) situated in the sleeve 13 of the tool spindle unit (10) is graspedby the second tongs (Z2) and pulled out through a return stroke step(H2) from the sleeve (13), and subsequently through pivoting of thetongs-type grab (ZG) by 180° about the horizontal axis (v) the firsttool (WZ) is positioned before the sleeve (13) and inserted in thesleeve (13) through execution of a--third--reversing stroke step, andthereafter through turning back of the console (40) by 90° about thevertical axis (w) and traveling about the reversing stroke step ismovable into the initial position in which the second tool (WZ) isinsertable in the tool magazine (14).
 6. Device according to claim 1wherein in the initial position of the tongs-type grab (ZG) a first tool(WZ) situated in the tool magazine (14) is grasped by the first tongs(Z1) and through traveling about a first stroke step and pivoting by 90°about the horizontal axis (v) as well as turning of the console (40) by90° about the vertical axis (w) as well as returning of the tongs-typegrab (ZG) by 90° about the horizontal axis (v) a second tool (WZ)situated in the sleeve (13) of the tool spindle unit (10) is grasped bythe second tongs (Z2) and pulled out by a second stroke step from thesleeve (13), and subsequently through pivoting of the tongs-type grab(ZG) by 180° about the horizontal axis (v) the first tool (WZ) ispositioned before the sleeve (13) and inserted in the sleeve (13)through execution of a--third--reversing stroke step, and thereafter ismoved through turning back of the console (40) by 90° about the verticalaxis (w) and traveling by the reversing stroke step into the initialposition in which the second tool (WZ) is insertable in the toolmagazine (14).
 7. Device according to claim 4, wherein the standardizedworkpiece pallets (WP) are provided with recesses (33) which are engagedby engagement elements (26) of the conveying path (20) for grasping andfurther transport of the workpiece pallets (WP) readied at the pickupsite (18) of the pallet magazine (PM) and in the machining position (BP)of the workpiece carrier (WT).
 8. Device according to the claim 7wherein the conveying path (20) is provided in form of a chain conveyor(27).
 9. Device according to claim 8, wherein the driving strand of thechain conveyor (27) is connected to the chain conveyor driving motor(28), with a drive shaft (38) being arranged in the horizontal pivotaxis (50) of the feeder (ZU) and a driving pinion (30) secured theretoand engaging the conveyor chain (29).
 10. Device according to the claim7 wherein the conveying path (20) includes two parallel threadedspindles (32), the threaded nuts (35) of which including engagementelements (34) engaging in recesses (33) of the workpiece pallets (WP).11. Device according to claim 10, wherein the threaded spindles (32) areprovided with right-handed thread and left-handed thread and/or drivenin opposition.
 12. Device according to claim 7 wherein the conveyingpath (20) is formed by two racks (46) which are driven in oppositedirection and provided on their bilateral, extendible ends withengagements elements (34) for bilateral simultaneous engagement in therecesses (33) of the workpiece pallets (WP) on the side of the pickupsite (18) and the side of the workpiece carrier (WT).
 13. Deviceaccording to claim 7 wherein the conveying path (20) is formed by twotelescopic rods (37) driven in opposition to each other and having onboth sides extendible ends provided with engagement elements(34) forsimultaneous bilateral engagement into the recesses (33) of theworkpiece pallets (WP) on the side of the pickup site (18) and the sideof the workpiece carrier (WT).
 14. Device according to claim 1 whereinin the initial position of the double tongs-type grab (ZG) a first tool(WZ) situated in the tool magazine (14) is grasped by the first tongs(Z1) and through movement by a stroke step and turning of the console(40) by 90° about the vertical axis (w) a second tool (WZ) situated inthe sleeve (13) of the tool spindle unit (10) is grasped by means of thesecond tongs (Z2) and pulled out from the sleeve (13) through a returnstroke step of the tool spindle unit (10) and that subsequently thefirst tool (WZ) is positionable before the sleeve (13) through pivotingof the tongs-type grab (ZG) by 180° about the horizontal axis (v) andinsertable into the sleeve through executing a--further--reversingreturn stroke step (R) and subsequently movable through turning back theconsole (40) by 90° about the vertical axis (w) and travel about thereversing stroke step (H2) into the initial position in which the secondtool (WZ) is insertable in the tool magazine (14).
 15. Device accordingto claim 1 wherein the first guiding path (43) is formed with an offsetsection positioned underneath the tool spindle unit (10) in workingposition (AP) and movable relative to the tool spindle unit (10) foreffecting a disengagement of the tool spindle unit (10) from the columnconsole (4).
 16. Device according to claim 1 and further comprisingmeans for lowering the column console (4) or its adapter element (45)for effecting a disengagement thereof from the tool spindle unit (10) inthe respective working position (AP).
 17. Device according to claim 1and further comprising connection means for linking the first guiding(43) to a second movement path (44) forming a stand-by position (16) fora number of tool spindle units (10, 11).
 18. Device according to claim17 wherein the first guiding or movement path (43) is rectilinear andthe second movement path (44), which is connected on both sides at aright angle to the end of the first movement path (43), forms a stand-byposition (16) for a plurality of tool spindle units (10, 11).
 19. Deviceaccording to claim 1 wherein the tool spindle units (10) are providedwith a synchronous motor arranged directly on the spindle shaft. 20.Device according to claim 19 wherein the frequency generator for thesynchronous motor is arranged in the area of the adapter element (45) ofthe column console (4) for detachable connection with the tool spindleunit (10) situated in working position (AP) in or on the column console(4).
 21. Device according to claim 20 wherein the adapter element (45)of the column console (4) and the attachment surfaces (46) of the toolspindle units (10) are provided with remote-controlled pressure fluidoperated fitting and armature devices and rapid connections for thecurrent transmission.
 22. Device according to claim 21, wherein theadapter element (45) are movable upwardly and downwardly relative to theconsole (4).
 23. Device according to claim 21 wherein the adapterelement (45) is equipped in the area of the attachment surface (46) withdovetail grooves or T-grooves for receiving the respective fitting railof the tool spindle unit (10).